Under FASB guidance exploratory well costs should continue to be capitalized when the well has found a sufficient quantity of reserves to justify its completion as a producing well and the Company is making sufficient progress assessing the reserves and the economic and operating viability of the project.

As of March 31, 2022, the Company had total capitalized exploratory well costs for continuing operations pending the determination of proved reserves of $172.7 million. The following table reflects the net changes in capitalized exploratory well costs during the three-month periods ended March 31, 2022 and 2021.


(Thousands of dollars)	2022		2021
Beginning balance at January 1	$	179,481	181,616
Additions pending the determination of proved reserves	3,698		785

Capitalized exploratory well costs charged to expense	(10,473)		—
Balance at March 31	$	172,706	182,401

The capitalized well costs charged to expense during 2022 represent expenditures related to the Cutthroat-1 exploration well in block SEAL-M-428 in the Sergipe-Alagoas Basin offshore Brazil. There were no hydrocarbons found in this well.

The following table provides an aging of capitalized exploratory well costs based on the date the drilling was completed for each individual well and the number of projects for which exploratory well costs have been capitalized. The projects are aged based on the last well drilled in the project.


	March 31,
	2022				2021

(Thousands of dollars)	Amount		No. of Wells	No. of Projects	Amount	No. of Wells	No. of Projects
Aging of capitalized well costs:
Zero to one year	$	2,810	2	2	—	—	—
One to two years	—		—	—	23,514	3	3
Two to three years	23,667		3	3	30,562	2	2
Three years or more	146,229		8	2	128,325	6	—
	$	172,706	13	7	182,401	11	5

Of the $169.9 million of exploratory well costs capitalized more than one year at March 31, 2022, $94.0 million is in Vietnam, $47.6 million is in the U.S., $15.3 million is in Mexico, $8.2 million is in Brunei, and $4.8 million is in Canada. In all geographical areas, either further appraisal or development drilling is planned and/or development studies/plans are in various stages of completion.

There were no impairments in the first quarter of 2022. In the first quarter of 2021, the Company recorded an impairment charge of $171.3 million for Terra Nova due to the status, including agreements with partners, of operating and production plans. Later in 2021, the Company acquired an additional 7.525% working interest at Terra Nova following a commercial agreement to sanction an asset life extension project.

There were no divestments in the first quarter of 2022. During the first quarter of 2021, the King’s Quay FPS was sold to ArcLight Capital Partners, LLC (ArcLight) for proceeds of $267.7 million, which reimbursed the Company for previously incurred capital expenditures.